This invention relates to the packaging art and has particular reference to an improved carton for packaging an electric lamp bulb, and to the improved lamp bulb package which results from the use of such carton.
It is customary in the electric lamp industry to package lamp bulbs by placing them in suitable containers which protect the bulbs from breakage and damage during shipment and also during display for purchase at the retail level. In the case of incandescent type lamps, this is generally accomplished by inserting the individual lamp bulb into a sleeve-like carton of rectangular cross-section that is fabricated from cardboard and is open at both ends. Retention of the lamp bulb in its inserted position within the carton is achieved in accordance with the prior art by various kinds of partitions that constitute integral parts of the carton and have apertures which interlockingly receive the enlarged or bulbous portion of the lamp.
For example, a paperboard carton for packaging a light bulb or similar fragile article that is of tubular sleeve-like configuration and has a pair of partition panels with openings which accommodate the bulbous portion of the inserted lamp and that also has a pair of tab portions which are located at one or both ends of the panels and lock the carton in its fully open and squared configuration is disclosed in U.S. Pat. No. 3,547,256 to Bolding. A lamp bulb carton of similar construction which has an internal partition structure formed by a pair of panels each having a pair of short flaps which resiliently grip the body portion of the inserted light bulb is disclosed in U.S. Pat. No. 3,820,707 to Fischer et al. The use of a pair of internal partition members each having a single opening and a single hinged flap for retaining and protecting the bulbous portion of an inserted lamp bulb is disclosed in U.S. Pat. No. 3,968,924 to Tyrseck.
A carton designed for packaging a pair of lamp bulbs which are separated from one another and locked within the carton by means of a partition structure that has suitable cut-outs and bulb-separating tabs or flaps is disclosed in U.S. Pat. Nos. 4,185,766 (Davidson et al.) and 4,231,510 (Beard).
A single-lamp carton which has an apertured panel that obliquely spans a corner of the erected carton and, in addition to locking the inserted lamp bulb in place, provides a bracing action that holds the open-ended carton in erected position is disclosed in U.S. Pat. No. 3,941,304 to Barbieri et al.
While the prior art cartons were generally satisfactory from the standpoint of retaining the lamp bulb or other article in its inserted position within the open-ended sleeve, they did not provide adequate protection for the packaged lamp and/or completely solve the problem created by the natural tendency of the loaded carton to return to its collapsed and flat condition. Most of the prior art cartons were also complicated and expensive to mass-produce and had to be set-up for loading by hand. These are important deficiencies, particularly in the case of lamp bulbs and similar articles that are packaged by automated equipment at high production speeds rather than by manual labor and must be stacked on store shelves or display units.
The aforementioned drawbacks are overcome in accordance with the present invention by making a single-lamp carton from suitable boxboard or the like that is cut and scored in such a manner that the inserted lamp bulb is not only securely held in place within the carton by a pair of apertured partition panels that provide an internal liner but coact with paired flaps which are coined from medial parts of the respective panels and are so shaped and arranged that they swing in opposite directions and form cradle-like structures that are pushed by the inserted lamp bulb into pressured engagement with the adjacent walls of the carton. One of the flaps in each pair is also of such length that it extends into and engages a corner-forming portion of the carton, such flaps being so oriented that they engage diagonally-opposite corners of the erected carton. The "criss-crossed" displacement of the paired flaps into cradle-like position, coupled with the forces which they generate by being pressed against the walls and corners of the carton, automatically centers the inserted lamp bulb in suspended position within the carton and locks the carton in fully erected "square" configuration. These self-centering and self-squaring features permit the carton to be erected and loaded with a lamp bulb in a very efficient manner by automatic high-speed packaging machines and provide lamp packs that can be readily stacked.